On his twenty-seventh birthday Simon Casey and fellow teachers Susan,Brian and Kurt get drunk and break into Summerdown Comprehensive where they work,stealing a bust of Shakespeare. Hung over next day after sleeping with policewoman Maggie Simon covers for a pupil whose attempt to tattoo himself goes wrong - for which he is rebuked by acting year head Jenny,whose bottom Brian ogles. Already scared that Jenny knows about his part in the break-in he falls foul of her for calling her lessons boring and is carpeted by Clare,the headmistress. He has also fallen for his father's intended Marcella but it is not reciprocated and he turns to Maggie for consolation.

Secretly fancying her Simon apologizes to Jenny. He chills out with pupil Arnie sharing a spliff but later Arnie is caught with cannabis on him. Kurt and Brian get into a panic when they realize that they are not prepared for Parents' Evening and bone up at the last minute but it is Simon who ends up in trouble when Jenny tells Arnie's parents about the cannabis. Clare suggests a police officer comes to lecture the school on drug abuse so Simon asks Maggie,who does well,but is not the only one to be surprised that he has not said she is his girl-friend. Susan and Jenny both apply to be Year Head and Susan gets the job but Simon is put out that she wants to celebrate with Jenny and not the lads.

Simon's father asks Marcella and her annoying little daughter - who pours milk into Simon's brief-case - to stay so Simon feels it best to leave. After a stay with boring science teacher Stephen he moves into Kurt and Brian's untidy bachelor pad but is amazed that they are even lazier than he is,interrupting his efforts at preparing lessons. Maggie is still annoyed with Simon for not acknowledging their relationship so,at Susan's suggestion,he cooks her a romantic meal. This does the trick and affords reconciliation despite their being caught in Brian's bed.

Sex education is now on the curriculum and,after facing down pupils' taunts,Simon advises Cheryl to dump her boyfriend Greg because he refuses to have sex with her. When it transpires that Greg is only abstaining because he has crabs Cheryl goes to see Susan,which lands Simon in trouble again. He also feels inferior because Maggie has had far more dangerous and adventurous sex positions than him though when they go to dinner with Susan and her husband Pete - whose marriage seems to be failing - he turns down Maggie's offer to do it in the bathroom. He does however make up for it back at the flat in Kurt's filthy bedroom - waking up to find Kurt in bed beside them.

When some of the students lock Jenny and Simon in the stationery cupboard for a prank all of Simon's lust for Jenny finally comes to the fore and,much to his surprise,she does not resist. Fed up with sleeping on the sofa in Kurt and Brian's untidy flat he agrees to move in with Maggie and they have a house-warming party. Simon is apprehensive when Jenny turns up but rather than spill the beans on him she leaves arm in arm with Brian.

Still on probation and not yet a permanent staff member Simon's attitude to work means he is supervised by Jenny. Susan finds her new responsibilities stressful,especially as her colleagues are unwilling to help share the burden.Then at an open evening where Kurt and shy school secretary Carol share a drink Peter storms in,reminding Susan that she should be at his works dinner. She runs out and,after admonishing Simon for not being supportive,takes time off. Simon impresses Jenny by his admission in class that he should have been more understanding to Susan but still lets Jenny visit her alone. However Susan is soon back at work,having dumped Peter.

The school is littered with nude photos with staff heads superimposed on the bodies. When Clare asks the teachers to incorporate this into lessons on sex pupil Pauline tells Simon that Bob,his interviewer for a permanent teaching post,ogled her breasts. Neither Jenny nor Susan,now staying with her,will intervene with Bob on Simon's behalf and Bob takes the ultimate confrontation very seriously,threatening to ruin Simon's chances. Fortunately Susan comes to the rescue and,after catching the porn distributor,Simon is in Clare's good books. After seeing another student go into labour now all he has to worry about is being best man at his father's wedding.

Despite nightmares in which he is nude in front of the interviewing panel Simon's job seems secure. However he gets into a heap of trouble when Liz,the other school secretary and a notorious gossip,erroneously leaves him with the impression that Jenny is jealous of Susan and trying to undermine her. This leads to a showdown at the end of term party with both Maggie and Jenny. However as Simon and Jenny find themselves sharing the same taxi once more their mutual passion comes to the fore and Simon leaves Maggie for her. Meanwhile Carol and Kurt continue to see each other.